Long-acting estradiol derivatives

ABSTRACT

C7-C12 and C15-17-cycloalkenyl ethers of estradiol-3-alkanoyl ester having contraceptive and estrogenic activity are obtained by reacting estradiol-3-alkanoyl-ester with a functional derivative of a cyclic ketone at a temperature higher than 70* C.

United States Patent Alberto Ercoli Milan;

Rinaldo Gardi, Carate Brianza (Milan); Romano Vitali, Casatenova (Como), all of [72] Inventors Italy [21] Appl. No. 884,008

[22] Filed Dec. 10, 1969 [45] Patented Nov. 30, 1971 [73] Assignee Warner-Lambert Company Morris Plains, NJ.

[32] Priority Dec. 11, 1968 [33] Italy [54] LONG-ACTING ESTRADIOL DERIVATIVES 5 Claims, No Drawings [52] U.S. Cl 260/397.5, 260/999 [5| Int. Cl C07c 169/08 [50] Field oiSearch 260/3975 Machine Searched Steroids [56] References Cited UNITED STATES PATENTS 3,135,744 6/1964 Ercoli et al. 26()/239.55 3,242,l98 3/1966 Ercoliet al. 260/3974 3,417,183 12/1968 Ercoli et al. 424/243 Primary Examiner-Henry A. French All0rneysAlbert H. Graddis, Henry E. Millson, Jr. and

Frank S. Chow ABSTRACT: C -C and C, -l7-cyc|oalkenyl ethers of estradiol-3-alkanoyl ester having contraceptive and estrogenic activity are obtained by reacting estradi0l-3-alkanoyl-ester with a functional derivative of a cyclic ketone at a temperature higher than 70 C.

LONG-ACTING ESTRADIOL DERIVATIVES This invention relates to novel long-acting steroids of the estrogenic series. More particularly, this invention relates to C-,C, l7-cycloalkenyl ethers of estradiol 3-esters and to novel compositions having prolonged contraceptive and estrogenic activity containing said C C,,l7-cycloalkenyl ethers of estradiol S-esters, as active ingredients.

l7-Esters of estradiol 3-esters, particularly the l7( 1- cycloalkenyl) ethers having five or six carbon atoms in the cycloaliphatic ring have been described as having enhanced oral uterotrophic activity (see for example British Pat. No. 1,072,828).

It has surprisingly been found now that C,C, 17-(lcycloalkenyl) ethers of estradiol 3-esters in which the cycloalkenyl ring in l7-position contains up to 12 carbon atoms exhibit an enhanced and protracted estrogenic activity and a marked contraceptive action.

So, this invention provides a new series of l7-( 1 -cycloalkenyl) ethers of estradiol 3-esters characterized by the following general formula:

(Ir-CH2 wherein R is selected from the group consisting of an unsubstituted straight or branched chain alkanoyl, a phenylalkanoyl and cycloalkylalkanoyl group containing up to carbon atoms and n is an integer of from one to six inclusive.

Typical examples of the above esters are: acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, trimethylacetyl, caproyl, enathoyl, capryloyl, phenylacetyl, a-phenylpropionyl, B-phenylpropionyl, a-phenylbutyryl, fl-phenylbutyryl, cyclopentylacetyl, cyclohexylacetyl, a-cyclopentylpropionyl, B-cyclopentylpropionyl and the like.

A further scope of the present invention is to disclose the compounds of formula l in which n represents 9: these estradiol 3-esters 17-( l -cyclopentadecenyl) ethers are also new and display interesting pharmacological activity.

The compounds of the invention exhibit a great and prolonged uterotrophic and contraceptive activity, particularly when administered parenterally. Thanks to their good solubility in oil they can be easily administered in a single dose to obtain prolonged activity.

Said products can usefully be used to induce estrogenic and contraceptive effects in warm blooded animals.

In accordance with the invention the novel compositions having prolonged contraceptive and estrogenic activity contain as active ingredients the compounds of the invention in admixture with an inert pharmaceutical carrier, in particular an oily solvent, such as, for example, sesame oil, peanut ,oil, corn oil, coconut oil, cottonseed oil, linseed oil, olive oil or tion are summarized in table ll, where it monoand diglycerides as well as synthetic triglycerides, that is esters of glycerol with high molecular weight aliphatic acids, either saturated or unsaturated. Such compositions may be in form of oily solutions in ampuls or multiple dose flacons containing the active ingredient in an amount of from about 0.1 to about mg., preferably from 0.5 to 20 mg. and may be administered by intramuscular or subcutaneous injections in a single dose.

PHARMACOLOGICAL DATA A. Determination of the prolonged uterotrophic activity The compounds under testing in solution of sesame oil were administered subcutaneously in a single dose of 0.05 umole to spayed rats weighing about 45-50 g. Groups of rats were sacrificed at the end of the 4th and 8th week, respectively, after the administration and the uterus weight of the treated and nontreated animals was detennined on a torsion balance. The increase of the uterus weight was considered as an index of the estrogenic activity.

The results obtained are summarized in table 1 in which the uterotrophic activity of some representative compounds of the invention, i.e. the l7-(l'-cyclooctenyl) ethers of estradiol 3- acetate, 3-isobutyrate and 3-trimethylacetate is compared with that of estradiol l7-enanthate, one of the most long-acting estrogenic agents known so far, and with two lower l7- cycloalkenyl esters already known, i.e. estradiol S-acetate l7- (l-cyclopentenyl) ether and estradiol 3-propionate l7-( 1 cyclohexenyl) ether.

Table I shows that the compounds according to the invention generally exhibit an estrogenic activity greater and much more prolonged than that of the reference compounds. More particularly, it results that 8 weeks after the treatment thecompounds of the invention still possess an uterotrophic activity at least equal to that displayed by estradiol l7-enanthate at the end of the 4th week, while the two known compounds are less active than estradiol 1 7-enanthate.

13. Determination of the contraceptive activity The contraceptive activity was determined in mature Wistar female rats weighting about -170 g. The compounds under testing, in sesame oil solution, were injected subcutaneously in a single dose of 0.5 ,umole and on the next day the treated animals were caged with fertile males and kept therewith till pregnant, and afterwards, on days 15-18 of pregnancy, the females were put in single cages. The results of this investigais indicated the situation on the th day after the administration. 7

TABLE II Number of rats 011 day 160 Treated Mls- Not Compounds administered (day 0) Delivered I carried Killed 2 Dead pregnant Controls 10 9 (27.6) 1 Estradlol3-acetate 17-(1-cyclooctenyl)eth 10 4 (137.5) 4 1 1 Estradiol S-trimethylacetate 17-(1-cyclooctenyl)ether 10 4 (147.6) 2 l Estradiol 3-isobutyrate 17-(lcyclooctenyl)ether. 10 3 (122. 3) 2 1 1 J 2 For difi'lcult delivery or probable reabsorptlon.

where R has the above defined meaning, with a functional derivative of a cyclic ketone of formula:

CHa-CH2 CHr-CH:

wherein n has the above defined meaning, at a temperature higher than 70 C. The term functional derivatives" means the typical derivatives of the ketones of formula ll above with lower aliphatic alcohols. Such derivatives are lower alkyl acetals or lower alkyl enol ethers containing from one to three carbon atoms as well as mixtures thereof as obtained by reaction of the free ketone with a lower alkyl orthoformate, the methyl and ethyl enol ethers and/or dimethyl and diethyl acetals being preferred. The reaction is carried out under anhydrous conditions, preferably in the presence of an acid catalyst and in an organic solvent, such as, for example benzene, toluene, xylene or dimethylformamide. After about I hour the reaction is over and the final product can be isolated according to usual procedures, for example by neutralizing the catalyst, if. any, evaporating the solvent and crystallizing and residue from a suitable solvent.

In order further to illustrate the invention the following examples are given.

EXAMPLE I An anhydrous mixture of 2 g. of estradiol 3-trimethylacetate and 20 mg. of p-toluenesulfonic acid in 700 ml. of toluene is treated with 2 ml. of cyclooctanone methyl enol ether and then distilled over a period of about 40 minutes. After addition of several drops of pyridine to neutralize the acid catalyst, the mixture is evaporated in vacuo and the solid residue thus obtained is taken up in methanol and filtered. The product, recrystallized from a methylene chloride-methanol mixture, yields 2.3 g. of estradiol 3-trimethylacetate l7-(l'-cyclooctenyl) ether, melting point l55-l57 C., [a],, =-+56 (dioxane, percent).

In the same manner, but using estradiol 3-acetate, estradiol 3-propionate and estradiol 3-isobutyrate as starting materials, estradiol 3-acetate l7-(l-cyclooctenyl) ether, melting point 1 l8-l20 C., [01],," =+64 (dioxane, c=0.5 percent), es--' tradiol 3-propionate l7-( 1 '-cyclooctenyl) ether, melting point 80-82 C., [a],, "='+6l" (dioxane, o=0.5 percent), and estradiol 3-isobutyrate 17-( l '-cyclooctenyl) ether, melting point l3ll33 C., [a],,"=+57 (dioxane, o=0.5 percent) are obtained, respectively.

Analogously using as cyclic ketone a mixture of methyl enol ether and dimethylacetal of exaltone (cyclopentadecanone) the corresponding estradiol 3-esters l7-(l'-cyclopentadecanone) ether are obtained.

5 EXAMPLE 2 An anhydrous mixture of 2 g. of estradiol 3-propionate, 3 ml. of cycloheptanone dimethyl acetal, mg. of pyridine tosylate and 700 ml. of toluene is distilled over a period of about 40 minutes. The acid catalyst is then neutralized with several drops of pyridine and the mixture is concentrated in vacuo to dryness. The residue taken up in a methylene chloride-methanol mixture yields the estradiol 3-propionate 17-( l -cycloheptenyl) ether.

EXAMPLE 3 An anhydrous mixture of 2 g. of estradiol 3-propionate and 20 mg. of p-toluenesulfonic acid in 700 ml. of toluene is treated with 2 ml. of cyclododecanone dimethyl acetal and then distilled over a period of about 40 minutes. By operating as in example 1, estradiol 3-propionate l7-( l'-cyclododecenyl) ether is obtained, melting point ll7-l l9 C., [011 +56.7 (dioxane, c=0.5 percent).

In the same manner, but using estradiol 3-enanthate and estradiol 3-caprylate as starting materials, estradiol 3-enanthate l7-( l '-cyclododecenyl) ETHER AND ESTRADIOL 3-caprylate l7-( 1 -cyclododecenyl) ether are obtained, respectively.

EXAMPLE 4 Five hundred milligrams of estradiol S-trimethylacetate l7- (l'-cyclooctenyl) ether is dissolved in 100 ml. of sesame oil and the solution is poured into 1 ml. ampuls so that each ampul contains 5 mg./ml. of the active substance.

EXAMPLE 5 A solution of 200 mg. of estradiol 3-isobutyrate l7-( l cyclododecenyl) ether in 100 ml. of sesame oil is poured into 1 ml. ampuls to obtain ampuls containing 2 mg./ml. of the active substance.

We claim:

1. A compound of the formula:

CHr-CH2 .J u,

CHr-CHt CHr-CH:

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 624, 113 Dated 11/30/71 Invent0r(s) Alberto Ercoli, Rinaldo Gardi, and Romano Vitali It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, Claim 1, lines 44-52, the formula appearing in brackets should be deleted:

/CH -CH II (CH CH CH (SEAL) Attest:

EDWARD M.FLEI'CHEB, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

2. Estradiol 3-trimethylacetate 17-(1''-cyclooctenyl) ether.
 3. Estradiol 3-isobutyrate 17-(1''-cyclooctenyl) ether.
 4. Estradiol 3-propionate 17-(1''-cyclooctenyl) ether.
 5. Estradiol 3-acetate 17-(1''-cyclooctenyl) ether. 